Question

In Pisum sativum, the stem may be tall (T) or dwarf (t). Calculate the probability of the offspring in cross Tt x TT which would be expected to be homozygous tall?

1/2

1/4

3/4

0​

Answer 1

Answer:

The answer is 3/4

Explanation:

TT×Tt=TT, TT, TT, Tt

Answer 2

Answer:

The probability of the offspring being homozygous tall in cross Tt xTT in the stem of Pisum sativum is 3/4.

Explanation:

• When a heterozygous tall (Tt) plant is crossed with a homozygous tall (TT) plant, the offsprings obtained would be TT, TT, TT, and Tt.

• In the cross, the tall gene is represented by 'T' and the dwarf gene is represented by 't'.
• The cross can be shown as follows:    

                    Parents:            TT               x               Tt    

                   Gametes:         T  T                           T     t        

                      Offspring:      TT      TT        TT      Tt

• Therefore, the probability of obtaining a homozygous tall would be 3/4.
• 3 TT: 1 Tt is the observed phenotypic ratio for the given cross.